Enzymatic synthesis of 2-deoxy-beta-glucosides and stereochemistry of beta-glicosidase from Sulfolobus solfataricus on glucal

The hyperthermophilic member of family 1 of the glycosyl hydrolases, the -glycosidase from the archaeon Sulfolobus solfataricus (Ss-gly), has been used for an efficient synthesis of -2-deoxyglucosides and for stereochemical studies of the reactions of glucal in the presence of alkyl and pyranosidic acceptors. Protonation of the double bond of glucal resulting in the equatorially disposed proton was observed and an indication of the protonating amino acid in the active site was obtained by the use of a mutant enzyme. The regioselectivity in the formation of -2-deoxyglucosides of pyranosidic acceptors is different from that reported for mesophilic biocatalysts.